ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 70 Number 1
The value of triploid, tetraploid, and hexaploid Napier grass derivatives as biomass and (or) forage
Pennisetum purpureum Schum. (Napier grass or elephantgrass) and hybrids of P. glaucum (L.) R. Br. (pearl millet) x P. purpureum have been evaluated for in vitro organic matter digestibility (IVOMD), neutral detergent fibre (NDF), lignin, crude protein (CP), and biochemical methane potential (BMP). Objectives of the study were to determine if the selected lines differed, and also how the plant components were different. Although Napier grass and the triploids and hexaploids derived from crosses to pearl millet have high biomass production, the quality of the feedstock is variable. To understand how plant components (leaf blades, sheaths, stems, and meristematic regions) differ in forage quality, four Pennisetum lines were harvested at four different dates. The meristematic zone (tissue above and including the most recent fully expanded leaf blade) was always the highest in IVOMD and CP (673 and 148 g kg-1), with declining IVOMD and CP values for blades, stems, and sheaths. Bottom sheaths were consistently lowest in both IVOMD and CP (354 and 29 g kg-1). Large differences in quantity of stem and leaf material and their ratios were observed between lines tested, but the quality of the various components from the triploid, tetraploid, and hexaploid lines were very similar.
Keywords: Napier grass; Forage; Polyploids; Biomass; Nutritive value